I'm still having the issue too, long after new plugs. I had it into two different BMWs at a $125 cost each time and they could not find a problem. Its definitely misfiring at idle, and usually simmers down once the car is warmed up. My rpms hang high too.
2007 BMW 335i, Jet Black, Sport, 19" Wheels, custom trim, m shifter, Procede v5 Rev.3
369rwhp, Best 1/4 12.8 @ 108
2003 Hyundai Tiburon GT, Supercharged (stage 2, 280whp), Full mods, meth, coilovers, wheels, full stereo
2004 Suzuki GSX-R600, flush signals, undertail delete, carbon fiber exhaust